The keypad is an input device for a number, math operation signs and the enter function. It is a very helpful tool for the accounting or financial business related people.
In the prior arts, there are some inconveniences in the usage of the keypad, especially when the keypad is coupled with a notebook computer. Some keys of the notebook keyboard (such as U or J) can be switched to character or numeric input mode by the Num Lock key, and the Num Lock mode of the external keypad that couples with the notebook will be independently switched but not synchronous with the notebook. Therefore, the Num Lock modes of these two devices may be different. But the final input result will be based on the Num Lock mode of the notebook, so the pressed keys of the external keypad are decided by the Num Lock modes of both the keypad and the notebook. Here comes a trouble: when a user wishes to input numbers by keypad, he must sets the Num Lock modes of both the keypad and notebook ON; but when the Num Lock mode of the notebook is ON, some keys of the notebook keyboard, such as U, J, etc., will become number keys. This will inhibit to input U or J via notebook keyboard when the Num Lock mode of keypad is ON, and reduces the convenience of the keypad usage.